Astronomical instrument



Aug. 28, 1945. r A MILLAR Re. 22,670

ASTRONOMICAL INSTRUMENT Original Filed March s, 1943 ATT RNEYS Reissued Aug. 28, 1945 UNITED STATES PATENT OFFICE ASTRONOMiCAL INSTRUMEN T' John A. 'Millar, East Orange, N. L, ass ijgnor.to

Ruth G. Millar, East Orange,- N. J. Original No. 2,349,188, dated May is, 1944, Serial No. 473,512, March 9, 1943 ApiSlicatioiifol reissue November 9, 1944, Serial NO. 562,575

. 12 Claims.

.en'tly adapted for 156 in only one of the two hemispheres; For World-wide navigation two complementary instruments would therefore be required including one for the Northern and one for the Southern Hemisphere.

It is an object of the invention to provide an lnstrumentality of the above type of simple, rugled and inexpensive construction, which may be readily set to locate-a star or constellation, or conversely to determine by reier'enc'e to a said star or constellation the location of the observer and which is universal in that it may be used at any point on the face of the lobe in the Northern orthe Southern Hemisphere and without resort to elaborate tables and without the need for computation or the likelihood of error. In the accompanying drawing in which is shown one OfzVfiIlO'LlS possible embodiments of the several features of the invention,

Fig. 1 is a perspective view of the instrument. v Fig. 2 is a viewin longitudinal cross-section taken-on line 2--2 of Fig. 1-.

Fig. 3 is a transverse sectional detail view taken on line 3 3 of Fig. 2, and 1 I v i Fig. {l is a fragmentary perspective View of a modification. l

Referring now to the drawing, the instrument involves a base Ill-having an upstanding U- shaped bracket II, desirably of sheet metal. Mounted between the legs of said bracketis a body l2, whichincludes a generally cylindrical holder cup l3 desirably of wood, but preferably of plastic, pivoted about a cross bolt I therethrough and retained-in any position of angular settingby a wing nut l5 tightened through washer ii-against one arm of the bracket, friction washers 11 being desirably interposed between the holder and the sides of the bracket. -.A lug I8 in the side wall of the holder rides in an arcuate slot I 9 in one side of the bracket, which has a latitude scale 20 thereon coacting with an index line II on the lug I8 and serving for convenient. setting of the instrument to the latitude, determined in any convexiientv way as by shooting the Pole Star, the Southern Cross or other point of reference. H f

' About the extremity 2'2 of thejholdc'r I3 is tele. scoped the lower end of'a sleeve 23 which abuts against a' 'peripheral' shoulder! near the outer end or said holder. Upon the upp r end oi the sleeve 23 is lodged a head, preferably a generally spherical dome structure 21 the flattened lower end 25 of which is slightly reduced and fitted into the upper end of the sleeve'23 to afford a peripheral ledge 24- Which rests firmly upon the upper end of the sleeve.

Aflixed as by screws 26 tcsaid flattened lower end are the wings 21 are U-shaped sheet metal bracket 28 in the cross arm of which is mounted a swivel hook 23 to which is hooked the upper end of a coil spring 30; axially through the holder cup l3 and the lower end of which is anchored about the cross bolt I4; so that the dome is resiliently pressed againstthe upper end of the sleeve, but may be; readily adjusted about the axis of the sleeve 23.

The dome isdoilirably of three pieces, including a pairof spherical segments 3| and 32 and I an interposed disk or declination ring 33 diametrically thereof combined into a unitary structure by the transverse bolt 34 axially therethrough, a wing nut 35 thereon tightening the partsin any desired setting. The spherical segments and the rin are desirably of suitable plastic such as phenolic plastic. Preferably flex ible disks 36 are in-torposedbetween the lateral faces of the decli-naticn ring and the spherical segments of the dome to minimize friction in adjustment, in the settingofthe declination ring which turns in a plane at right angles to that in which the. dome is turned. The declination ring a complete disk which extends below the flat 25 of th e dome and between the arms of bracket 28, the wings 2'1 of which are secured to spherical segments 3! and 32 respectively, as shown.

The declinationringcarries a hanger 31 for accommodating a tube 38, small telescope or the like for convenience in shooting a star. The hanger is made at a sheet-metal strap which has the circular. clamping portion 31 and the extremities 39 of which-extend in -superposed relation snugly into a corresponding slot 40 in the declination ring into which they are secured by apair of rivets, y

The uppermost exposed end '0f the holder l3 immediatelybeIow the sleeve 23 has a peripheral calendar scale 42 thereabout, v the divisions of which run to the rim thereof, as shown. he abutting endof" the sleeve. 23 has an hour scale 43' tliereabout, desirably running 'irom zero to 24. The holder [3 desirabl-y has a periphcral rib 44 unitary therewith, defining-a eriphera1 ledge 45 at its top and immediately below the date scale 42. About the face of. the peripheral rib purpose, the sleeve desirably is equipped with a bolt 41 protruding through a slot 48 longitudinally of the collar and a nut 49 about the stud serves to lock the collar eitherin its uppermost position as .shown in Fig. 1, with the stud engagtable the latitude and longitude may be readily determined by use of the instrument.

Upon crossing the equator, the instrument may be immediately converted for use in the Southern Hemisphere by simple adjustments. Nut 49 is loosened to lower the collar 46 for covering the black time ring 43 and the black date ring 42 so that the'collar 46 rests upon the peripheral ledge 45, and the complementary or red time scale 43' is now in juxtaposition to the complementary or red date scale 42'. The declination ring is rotary displacement relative thereto. For that 7 ing the lower end of the slot 48, or-in lowermost position in which the collar abuts the peripheral ledge at the top of the lower scale 42'. the lower end of the collar 46 is an hour scale 43 desirably running up to 24, whichis complementary to hour scale 43 ,on the sleeve 23. that is to say, the progression of hours thereof is clock.-

wise when viewed from the top of, the instrument,

whereas that on the sleeve is counterclockwise and the sum of each registering pairv of numerals on the two hour scales is 24.

About the extremeupper end of the sleeve 23 is an hour angle scale by which the dome may be set for sidereal hour angle, byreference to the median peripheral line 5|. about the declination ring 33. The hour angle scales are desirably in two sets as shown, one from zero to 360 degrees peripherally about the sleeve in clockwise and the other in counterclockwise direction. On the declination ring 33 a scale desirably imprinted on a band 52 thereabout, for setting or reading of declination, by reference to an index line 53 on the equator of the dome. 1

Preferably the calendar scale 42 and the associated hour scale 43 are imprinted-in black. The complementary scales, that is, the lower calendar scale 42' and the hour scale 43' on the collar 45 are of contrasting color such as red.

The hour angle scale readings 50 that correspond to the hour scale 43 are likewise printed in black and the complementary scale that corresponds to hour scale 43' is in red. The scales in black servefor readings in the Northern Hemisphere and those in red for the Southern.

Similarly the scale readings on the declination ring are in two sets from zero to 90, and each has associated plus and minus marks to designate positive or negative declination, designated in black at one side and in red at the other for use respectively in the Northern and Southern Hemispheres.

The manner of use of the instrument will be apparent from the above description and need be but briefiy'setforth. The clamp 31 which is located at the 90 degree scale division of the declination scale 52 will be pointed to the pole star when the index line 2| is set to the'correct latitude. The sleeve 23 is then turned to bring the local time read on the lower time scale 43 thereof into registry with the date on the associated calendar ring 42. The dome 24 is then turned to the sidereal hour angle or right ascension of the constellation-or star of ref erence, and the declinationring 33 is' adjusted to the declination of such star, whereupon such star or constellation is located through tube 38. Conversely, when a given star is identified and its declination and its right ascension are known from a About a complementary angle scale 43 which turned until the diameter of tube 38 is reversed so that the Southern Cross rather than the pole star may be used as the point of reference. The instrument is now used exactly as above described except that only the red scales or the red symbols are used. Only the red calendar scale 42' and thered time scale 43 are now exposed for use. The set of red hour angle readings on scale 50 now serve for right ascension readings.

The. red plus or minus symbols in connection with the readings on'the scale 52 now serve for makingdeclination readings.

The embodiment of Fig. 4 shows in perspective view a fragment merely, of an instrument identical in construction with thatin Figs. 1 to 3, but having a different system of scale markings, which renders the device especially useful for navigation purposes. Y

Instead of the calendar scale 42 of Fig. 1, there is employed an angle scale 42 (0 degrees to 360 degrees) with the zero line corresponding to that for March 21 on the embodiment of Fig. 1. The complementary calendar scale 42 of Fig. 1 is re placed by the complentary angle-scale 42 .which like scale 42'runs in reverse direction. 1

The hour scale 43 of Fig. 1 is replaced by. an anglescale 43 (0 to 360 degrees) and the complementary hour scale 43 of Fig. 1 is replaced by like scale 43' runs in reverse direction.

The scale 50 at the upper end of the sleeve in Fig. 1 is replaced by a longitudinal angle scale 50, the zero marking of which i aligned'with the zero marking on the scales 43 and 43 and the scale markings of which run to degrees in each direction. The declination scale 5| is identicalwith scale 5 lof Fig. l. p

In use of instrument of Fig. 4,a navigator equipped with the usual American Air Almanac, the Ephemeris or the Nautical Almanac and also with a clock'showing Greenwich'time, can readily determine his position to within one degree of longitude. For this purpose, the latitude is determined by shootin the Pole Star andis read from the latitude scale. The sidereal hour angle of any selected star or planet is determined from the Almanac. or Ephemeris for the dateat-the particular Greenwich time read on the clock. The angle on scale'43 is set into registry on scale 42 with the Greenwich hour angle of Aries, which construction,'and many aparently widely. differ ent embodiments of this invention could b'e'made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as. illustrative and not in a limiting sense.

:Having thus described. my' invention, what I,

claim as'new and desire to'secure by Letters Pat'- ent'of the United States is: J

x 1. A; universal astronomical instrument "comprising a-base having a brackeqa generallycylindrical. body having a horizontal pivot mount-in said bracket fo-rlatitude adjustment in a vertical plane, the upper end of said body having a rotary dome adjustable about the axis of the body, an associated scale therebelow', said dome including a declination ring adjustable in a plane at right angles to that for adjusting the dome, said cylindrical body having a first scale thereabout, and including a rotatable sleeve having a second scale thereabout and adjoining said first scale, a collar encompassing said sleeve and having a scale thereabout complementary to that on the sleeve, said collar bein afiixed with respect to said sleeve for rotary displacement in unison therewith but longitudinally slidable thereon, said collar in one setting exposing the scale on the body and the associated scale on the sleeve and in the other adjustment concealing said scales, and a scale about said body complementary to the first scale and coacting in the latter adjustment with the scale on the collar.

2. The combination recited in claim 1 in which the scales on the cylindrical body are calender scales and the scales on the lower endof the sleeve as well as those on the collar are hour scales.

3. The combination recited in claim 1 in which each scale of the two sets of complementary scales is an angle scale.

4. A universal astronomical instrument comprising a base and a generally cylindrical body having a peripheral ledge near the top thereof, said body including a cylindrical mounting holder pivotally mounted on said base for latitude adjustment thereof, a sleeve telescoped upon the upper end of said holder and abutting said ledge, and a dome protruding from and telescoped at its lower part into the upper end of said sleeve and mounted for rotary setting thereof, said dome including a diametral rotarily adjustable declination ring, said holder and said sleeve having coacting scales respectively about their abutting ends, a collar encircling said sleeve and mounted for rotary displacement therewith, but longitudinally adjustable'thereon; said collar having a scale about one edge thereof complementary to that on said sleeve, and said holder having a scale thereabout coacting therewith and complementary to the first mentioned scale thereabout, said collar in one position thereof exposing the first mentioned coacting scales and in the other and the upper end of the slot in the other extremity. v

6. A universal astronomical instrument comprising a cylindrical-mounting holder having a pair of complementary scales thereabout, the

upper scale being on a slightly smaller diameter than the lower scale to define a peripheral ledge therebetween, a sleeve telescoped over the upper extremity of said holder and abutting at its lower end against the upper scale and having a scale thereabout coacting with said upper scale,

a collar-encircling said sleeve and affixed with respect thereto' for rotary adjustment therewith, flit-1531183118 connecting said collar to said sleeve to permit longitudinal'displacement of said col-- lar=along said sleeve-t0 abut said peripheral ledge for juxtapositiontoxth lower-scale and for concealment of the upper scale and its associated scale, said collar having a complementary scale near its lower edge coacting with the lower scale.

7. A universal astronomical instrument comprising a base, a generally cylindrical body pivotally mounted thereon for latitude adjustment, said body including a cylindrical holder and a coaxial sleeve rotarily adjustable thereabout for date setting, and a dome coaxial with and rotarily adjustable about the upper end of the sleeve for right ascension setting, said dome having a declination ring rotarily adjustable diametrically thereof for declination setting, said body having complementary sets of date and hour scales for use respectively in the Northern and Southern Hemispheres and including means for concealing one set of said scales when the other set is in use, a pair of complementary hour angle scales about the upper end of the sleeve and a pair of complementary declination scales about the declination ring for use respectively in the Northern and Southern Hemispheres.

8. A navigation instrument comprising a base, a generally cylindrical body pivotally mounted thereon having latitude adjustment, said body including a cylindrical holder having a Greenwich hour angle scale thereabout and a coaxial sleeve rotarily adjustable thereabout, having a sidereal hour angle scale thereabout at its lower end coacting with that on said body, the upper end of said sleeve having a longitudinal angle scale thereabout, a dome coaxial with and rotarily adjustable about the upper end of the sleeve, said dome having a declination ring rotarily adjustable diametrically thereof.

9. The combination recited in claim 8 in which the sleeve has a collar thereabout affixed with respect thereto for rotary adjustment therewith and longitudinal displacement thereof along said sleeve, said collar having a sidereal hour angle scale at the lower edge thereof complementary to that on said sleeve, said body having a second Greenwich hour angle scale thereon complementary to and adjacent the other Greenwich hour scale thereon.

10. A universal astronomical device having a base, a cylindrical body, a pivot bolt therethrough mounting said body for adjustment thereof in a vertical plane for latitude setting, said body having a hollow cylinder, a dome protruding from the upper part of said cylinder and having a fiattened lower part within said cylinder, a bracket affixed to said flattened part and within said cylinder, said bracket having a hook at the lower end thereof, and a coil spring connecting said hook to said pivot bolt, said dome comprising a pair of spherical segments and an intervening declination ring, and a transverse bolt 'holding said latter parts assembled, said ring having a hanger affixed therein affording a socket for accommodating apointer.

11. The combination recited in claim 10 in which the hanger comprises a strap presenting a collar for gripping a pointer, the ends of said strap being in superposed relation, extending into a corresponding cavity in the declination ring and being riveted in place therein.

12. A navigation instrument comprising a base, a body pivotally mounted thereon having latitude adjustment, said body including' a, part-having a Greenwich hour angleof Aries" scale :thereabout at one extremity thereof, and a coaxial member rotarily adjustable thereabout having -.a sidereal hour angle scale thereabout contiguous to and co-acting with said Greenwich hour angle of Aries scale on said body, .the other. extremity of said member having a longitudinal scale thereabout, a head with a declination scale coaxial with and rotarily adjustable about the 1ongitu-' dinal scale of said member, said head having a sighting device rotarily adjustable diametrically thereon. Y JOHN A. MILLAR. 

